The subject matter disclosed herein relates generally to magnetic resonance imaging (MRI) systems, and more particularly to systems and methods for adjustable head coils for use in conjunction with MRI systems.
MRI systems generally include a magnet to create a main magnetic field with gradient magnets exciting magnetic moments within the main magnetic field to acquire MRI data. Further, such systems also typically include a number of radio-frequency (RF) coils for receiving the MRI data that is provided to a processing unit for forming an image.
MRI images typically take a fairly long time to acquire, for example, between 15 and 45 minutes or more. During the acquisition time, the part of the body being imaged must remain generally still. For example, in order to acquire an MRI image of a patient's head, the patient is typically placed on a table with the head of the patient enclosed within one or more receive RF coil units for receiving information, such as by detecting an NMR signal. Because the size of adult heads are fairly uniform, these units typically are available in a one-size-fits-all unit, or with relatively small amounts of possible adjustment.
Children, however, experience a relatively large change in the size of their heads from birth until approximately the age of eight years old. For such children, the positioning of coils in an adult unit places the receive RF coils more than a desirable distance from their heads, resulting in reduced image quality. Further still, the distance between the child's head and head coil unit allows movement of the head during the scan, which can reduce image quality and/or require additional scans to be taken.
Some known systems attempt to address movement of heads during MRI scanning. For example, a number of pillows or cushions or other positioners may be placed in the unit interposed between the receive RE coils and the patient's head in an effort to stabilize the patient's head. Such systems, however, can be uncomfortable because the cushions are improperly sized and overly restrictive and uncomfortable. Also the use of pillows or cushions does not provide for easily controllable adjustability and/or a wide range of adjustability. Moreover, the receive RF coils remain placed an undesirably large distance from the patient's head resulting in reduced image quality. Further still, the use of such pillows or cushions packed into an adult sized unit surrounding a child's head can easily result in discomfort as well as feelings of claustrophobia or other unease.
Moreover, children especially can have significant difficulty remaining still for the required amount of time, especially in light of the feelings of claustrophobia or other unease. Accordingly, anesthesia may be used to render the child unconscious during a procedure, to prevent movement of the head. Anesthesia, however, is an expensive measure, and not without health risk to the child. Elimination of the use of anesthesia would result in a safer and less expensive scanning procedure.